Jeff,

A couple of points. First N-Tier system design has nothing to do with any particular technology for implementation. It can be used with a variety of technologies.

As for the client, they will probably be very gratefull when you can provide an Excel sheet that accesses their data and enforces all of their rules without a lot of work. You can only do this if Excel can use the same business rules enforcement code that the VFP app uses.

Once the N-Tier design is accomplished, then variety of differing front ends you can implement is only limited by the ability of a particular front end to participate in the implementation technology.

As for VFP being positioned as a middle tier development tool, I think that is absolutely wonderful. VFP, in its present state, competes with every other product in Visual Studio. This fact presents a large problem for Microsoft marketing. If they promote VFP they do it at the cost of other products. VB far outsells VFP and no one in their right mind would market VFP to steal from the VB user base. MS makes a lot more money from sales of SQL Server than from VFP, so again MS is not motivated to market VFP against SQL Server.

With VFP being positioned at the middle tier, it becomes a more focused product and MS can market it as such without hurting the sales of the other tools. What you ultimately do with VFP is your business, but having MS says good things about it will certainly help in getting clients to go for it.

You may not see it today, but the trend that is going on is for larger systems that incorporate many divergent tools in their composition. This trend will cause us to rethink how we do things so that our efforts are usable across many independant pieces within an application. Object Orientation, ActiveX, COM, DCOM, and other technologies are the implementation tools for this effort.

Whether you or I like DNA or not is irrelavent, DNA (or whatever it morphs into) is a technology that is necessary for the long term survival in an industry that thrives on change. If the technology was from IBM or ATT and was called something else, it would still be a necessary thing to learn and understand. It is possible to understand N-Tier design, actually implement it, and use it without knowing all of the minutia of DNA. In fact, one of the design goals of DNA is that the tools we use will implement it in a way that we can use it without being bothered by its implementation details.

I know I have put activeX controls in forms and have them work without knowing anything at all about how ActiveX technology in Windows works.